The present invention relates to an apparatus for sorting and removing undesirable objects from a feed belt conveyor, which belt passes an inspection station, while a downstream of the inspection station there is arranged a "trapdoor" and subsequently a discharge conveyor, enabling the undesirable objects to be discharged through the trapdoor, which undesirable objects upstream of the trapdoor can be defined as such by human or automatic detection, while the location of the objects in question can for instance be determined by a "tracking" memory (shift register) and remains known at least as far as the trapdoor.
Such an apparatus is disclosed in European patent application No. 0 092 989. In this prior art apparatus for sorting potatoes, use is made of a plurality of spaced apart, superimposed belt conveyors. Underneath the discharge end of the feed belt conveyor, there are disposed a plurality of flaps operable by cylinders. As soon as an undesirable potato passes the discharge end, the flap is moved outwardly, so that the undesirable potato falls onto a cross-conveyor disposed above the discharge belt conveyor. When the flap is not operated, the good potatoes will fall directly downwardly onto the longitudinally arranged discharge conveyor.
Such an apparatus is entirely unsuitable for sorting and removing eggs and the like vulnerable products.
SUMMARY OF THE INVENTION
It is an object of the present invention to eliminate the above drawback.
To this effect an apparatus of the above described type adapted in particular for processing vulnerable objects, such as eggs, is characterized in that the feed belt conveyor and the discharge belt conveyor are substantially aligned, and at least adjacent the "trapdoor" disposed between the said belts, there is arranged a turnstile, a chain having carriers (FIG. 2) or the like. As a result, a "soft" treatment of the good objects is ensured, while also the undesirable objects are gently removed from the transport path.
By arranging a weighing element downstream of the "trapdoor", a very short sorting apparatus can be obtained, where the undesirable objects are removed already before the weighing.
In a further elaboration of the present invention, the "trapdoor" may comprise a vertically reciprocatable fork-shaped member whose prongs during their movement can pass along the teeth of a guideplate arranged at an acute angle to the vertical. The downstream end of the guideplate may be fixedly connected to a discharge trough.
A different embodiment of the "trapdoor" may comprise a flap disposed in the discharge path for the eggs, which flap is rotatably attached to a frame or the like at the downstream end.
Also the "trapdoor" may consist of two independently vertically movable elements, the top ends of which are designed in such a manner that in the lowest mutual position they form a carrier for the eggs, and a "trapdoor" in an elevated position of one of the movable elements.
It has been experimentally found that the apparatus according to the present invention enables an inspection twice as quick, while the operator gets less tired.
In a further elaboration of the present invention, there may be arranged above the vertically movable elements, a conveying system having grippers, as described in Dutch Pat. No. 166,658, corresponding to U.S. Pat. No. 4,068,882.
The further transport, downstream of the "trapdoor", can take place by means of a "hare's jump" system, a double chain having carrier elements or another conveying element.
Besides, as known per se, guideplates may be arranged between the various conveying elements disposed in the path of motion of the eggs.